Of course its major barrier to entry, the main reason its usage is so low (apart from lacking any benefit of nostr:npub1sg6plzptd64u62a878hep2kev88swjh3tw00gjsfl8f237lmu63q0uf63m's endorsement, promotion, and financial subsidy) is that you MUST establish LN liquidity to use the app at all.

But, once that hurdle is lept, you have booste, direct payments, staking as anti-spam mitigation, and the ability to subscribe to other users (for instance I "subscribed" to my wife's account for 2000 sats per week to ensure that she'd have plenty of chat funds without having to ask nor fuss with BlueWallet, etc).

Also Sphinx supports Jitsi video conferencing from within the app.

I don't want this to become a pissing contest. Bit maybe your criteria for "best" are tautological? Or perhaps you're just unaware of the alternatives.